Elevator photo-cell by-pass control



Feb. 2, 1965 w. M. KIELY 3,168,164

ELEVATOR PHOTO-CELL BY-PASS CONTROL Filed Oct. 3, 1962 INVENTOR. WILLIAM M KIELY ATTORNEY.

4, United States Patent. -()fifice 3,168,164 Patented Feb. 2., 1965 3,168,164 ELEVATOR PHOTO-CELL BY-PASS CONTROL William M. Kiely, Closter, N.J., assignor to Elevator Specialties Corp., County of Bronx, N.Y., a corporation of New York Filed Oct. 3, 1962, Set. No. 228,067 Claims. (Cl. 187-29) This invention relates in general to elevators, and more specifically to a control for actuating a by-pass system used in elevator cars.

In manually operated elevators there is generally an attendant who can physically control the loading and unloading of an elevator car and consequently, the operator can manually determine whether to by-pass a floor or stop. In automatically operated elevators, the judgment and physical control of an operator is not available. Therefore, unless some means are provided for controlling the by-pass system, it is not possible to predetermine the stops which an elevator will make. This predetermination is, of course, highly desirable.

Therefore, an object of this invention is to provide a novel manner of controlling the by-pass system of an elevator.

Another object is to provide a control which is particularly adapted for use in automatic elevators that is relatively simple in structure, that is easy and relatively inexpensive to install, and that is positive in operation.

Still another object is to provide a control which will permit an elevator car to bypass succeeding stops so as to positively prohibit the pickup of additional passengers when the car is loaded to a predetermined capacity.

In accordance with this invention the foregoing objects, and other features and advantages are attained by a light source located in the car cooperatively associated with a novel load limiting circuit which includes plurality of light responsive means, as for example, photoelectric cells which are arranged in a circuit together with a relay and a switching means responsive to the photoelectric cells for energizing and tie-energizing the relay. The arrangement is such that when the elevator car is loaded to a predetermined capacity, the photoelectric cell causes the switching means to activate the relay which then causes a by-pass circuit to be energized. Actuation or" the by-pass circuit in turn permits the elevator to automatically bypass the next succeeding passenger pickup stop.

The light responsive means, in accordance with the illustrated embodiment of the invention, are spaced about the walls of the elevator adjacent the floor and they are electrically connected in parallel with respect to one another in the load limiting circuit. The arrangement is such that so long as the light responsive means see a predetermined amount of light, which emanates from the light source, the switching means responsive thereto is prevented from energizingthe relay and thereby the by-pass circuit ismaintained in an inactive or inoperative state. When the elevator is loaded to a given capacity, the passengers, therein, as a'group, will interrupt a portion of the light emanating from the light source in the ceiling. When the amount of light which the photoelectric cells are able to see'is'reduced to a predetermined level, which can be adjusted toindicate a given number of passengers standing in the elevator, the switching means is activated to energize the relayf Actuation of the relay in turn energizes the by-pass circuit which permits the elevator to automatically by-pass the next passenger pickup stop.

'The arrangement is such that the by-passing circuit will remain activated until some of the passengers have been thereby tie-energizing the by-passing circuit. As a result, the elevator is again able to make passenger stops until the number of passengers have again reached predetermined capacity and the cycle repeated.

A feature of this invention resides in the provision of a light source operatively associated with a plurality of light responsive means connected in a circuit for automatically controlling the energization and de-energization of a by-passing circuit permitting an elevator car to bypass succeeding passenger stops when filled to a given capacity.

Other features and advantages will become more readily apparent when considered in view of the specification and drawings in which:

FIG. 1 is a partial perspective view of an automatic elevator car embodying the instant invention and which is illustrated as being only partially loaded.

FIG. 2 is a sectional view taken along lines 2-2 of FIG. 1.

FIG. 3 is a schematic wiring diagram illustrating an embodiment of the novel circuit of this invention.

Referring to the drawings there is shown in FIG. 1 a perspective view of an elevator car 10. The car comprises essentially four upright enclosing walls, of which only the rear wall 11 and side wall 12 are shown together with the ceiling 14, and floor 15. In accordance with this invention, a light source is located in the car 10. While the light source is illustrated as being located centrally of the ceiling 14 so that the rays or beams of light radiate therefrom in all directions in a uniform manner,

'it will be understood that this position is shown for de- .17, as will be hereinafter described.

FIG. 2 illustrates a typical manner which the photoelectric cells 16 may be mounted in the walls of the elevator car. It will be observed that a flanged sleeve 18 is fitted into a hole 12a formed in the wall of the car 10, and

the photoelectric cell 16 is positioned in the bore 18a of sleeve 18. A suitable lock nut 20 and washer 21 are used to hold the sleeve 18 in place.

As shown in FIG. 3 the circuit 17 includes a pair of terminals 25 and 26 which are connected to a suitable source of electrical energy, as for example a source of AC. One of the terminals 25 is connected by means of conductors 27 and 28 to the cathode 29 of a triode electronic valve or tube 30. Connected in series with the cathode 29 is a voltage dropping resistor 31.

The other terminal 26 of the circuit is connected by a .or break this circuit, as will be hereinafter described.

The arrangement is such that when the relay coil 33 is energized, the relay contacts 36 operatively associated therewith are closed, thus efiecting energization of the by-pass circuit which permits the elevator car to by-pass succeeding passenger pickup stops.

To prevent the chattering of contacts 36 during the operation or energization ofthe relay coil 33, a filter condenser 38 is connected across the coil 33 in parallel therewith.

In accordance with this invention, the plurality of photoelectric cells are connected in the controlling por-' tion of the circuit. As shown, the photoelectric cells are connected in parallel with respect to one another between conductors 39 and 40. Conductor 39 in turn is electrically connected by a conductor 41 to the juncture defined by terminal conductor 27 and cathode conductor 28. Conductor 46, to which the other ends of the photoelectric cells are attached, is electrically connected through conductor 42 to terminal conductor 32. Connected in series with the several parallel connected photoelectric cells 16 is a potentiometer 43 and a grid limiting resistor 44, the potentiometer 43 serving to adjust the circuit.

The grid 45 of the triode 30 is connected by a conductor 46 to conductor 42, as shown, and a grid bias resistor 47 is connected in series with the photoelectric cells 16 between point B and conductor 39 of the photoelectric cells block. 7

The operation of the circuit described is as follows:

When the light 13 in the elevator is energized and with the elevator free of passengers, the photoelectric cells are able to sense or see the presence of light within the elevator car. Therefore, the photoelectric cells are rendered highly conductive. Since the photoelectric cells are rendered conductive by the sensing of the light, the current flow is had in the circuit through conductors 27, 41, through the parallel connected photoelectric cells 16, and conductors 42 and 32. Furthermore, insuflicient current fiow is had through the triode valve 30 or switching means, to efiFect energization of the relay coil. Since the relay coil 33 is not energized, the relay contacts 36 actuated thereby, are maintained in their open condition or state, thus maintaining the by-pass circuit 37 de-energized. In this condition the elevator may be operated to pick up passengers at any stop indicating the same. As more and more passengers enter the elevator car, the amount of light received by the photoelectric cells is gradually diminished, for the passengers stand between the light source 13 and the photoelectric cells 16. When the light received by the photoelectric cells is diminished, the resistance of the respecive cells 16 tends to increase, rendering them less and less conductive. As the resistance of the photoelectric cells increases, a voltage drop occurs between points A and B. When the voltage drop reaches a predetermined value, the difference in the potential between the components of the triode becomes such that a current flow is established therethrough. When the current flow through the triode 30 attains a given amperage, coil 33 of the relay connected in series therewith is energized thereby causing the relay contacts 36 to be closed, whereby the by-pass circuit becomes energized. The arrangement is such that the by-pass circuit 37 is maintained in an energized state so long as the photoelectric cells are maintained highly resistant, that is, maintained in a substantially non-conductive state due to the reduced amount of light received thereby as a result of the passengers obstructing the light. As passengers are discharged from the elevator car, more of the light will fall upon the photoelectric cells, whereupon the photoelectric cells are again rendered conductive thereby permitting the current flow to be by-passed around the triode switching means. Consequently, the relay becomes de-energized and the by-pass circuit is opened.

lems of overloading.

. While the instant circuit has been described with a triode tube 30 which is rendered responsive to the photoelectric cells and utilized as a switching means for effecting energizing and de-energizing the coil 33, it will be understood that a transistor may be utilized in lieu thereof. Substitution of a transistor in the circuit will functior as the full equipment of the triode tube 30 described From the foregoing description it will be readily apparent that the described arrangement provides for a relatively novel, inexpensive and positive acting load limiting means which is particularly adapted for use in automatically operated elevator cars. While the instant invention has been disclosed with reference to a particular embodiment thereof, it will be appreciated that the invention is not to be taken as limited to all the details thereof as modification and variations may be made without departing from the spirit and scope of this invention.

What is claimed is:

1. In combination with an elevator car, an overload limiting means comprising a light source located in the elevator car, a series of light responsive means spaced about the walls of the car, a relay adapted to be actuated to effect the by-passing of a stop when said car is loaded to a predetermined maximum safe capacity, said relay being connected in a circuit with said light responsive means whereby said relay is actuated when a predetermined amount of light beaming from said light source on said light responsive means is interrupted by the load carried in the elevator.

2. In combination with an elevator car, an overload limiting means comprising a light source located in the elevator car, a series of light responsive means spaced about the walls of the car, a relay adapted to be actuated to eifect by the by-passing of a stop when said car is loaded to a predetermined maximum safe capacity, said relay being connected in circuit with said light responsive means whereby said relay being actuated when a predetermined amount of light beaming from said light source on said light responsive means is interrupted by the load carried in the elevator, and a switching means disposed in series with said relay, said switching means being responsive to said light responsive means.

3. For use in an elevator car, a passenger overload limiting means comprising a light source located in the elevator car, and a circuit including a series of light responsive means spaced about the walls of the car, said light responsive means being rendered conductive by sensing the rays of said light source and non-conductive by the absence of light rays from said light source, a relay connected in said circuit in parallel with said light responsive means, and switching means connected in series with said relay for permitting a current flow therethrough for energizing the same when said light responsive means are rendered substantially non-conductive due to the presence of a predetermined number of passengers in the elevator, and said switching means opening the circuit to said relay when said light responsive means are rendered conductive by less than said predetermined number of passengers.

4. For use in an elevator car, a loading limiting means comprising a light source located in the top of the elevator car, and a circuit including a series of light responsive means spaced about the walls adjacent the floor of the car, said light responsive means being rendered conductive by sensing the rays of said light source and nonconductive by the obstruction of light rays from said light source, a relay connected in said circuit in parallel with said light responsive means, and switching means connected in series with said relay for permitting a current flow therethrough to energize said relay when said light responsive means are rendered substantially non-conductive by the presence of predetermined number of passengers in the elevator, and said switching means opening the circuit to said relay when said light responsive means are rendered conductive by the absence of less than said predetermined number of passengers, said switching means including a triode electronic valve,

5. For use in an elevator car, a load controlling means comprising:

(a) a light source centrally located at the top of an elevator car,

([1) a load controlling circuit responsive to said light source,

() said circuit including a plurality of photoelectric cells spaced in the walls of said elevator adjacent to the floor thereof whereby said cells are rendered conductive by sensing light rays from said source and non-conductive by the obstruction of said light rays from said source,

(0.) said cells being connected in parallel with respect to one another,

(2) a relay coil connected in parallel to said photoelectric cells,

(f) switching means connected in said circuit in series with said relay coil for permitting a current flow therethrough for energizing said relay when said cells are rendered substantially non-conductive by the absence of light falling thereon,

(g) said switching means including a triode electronic valve having a cathode, a grid and an anode,

(h) said cathode being connected to one side of said parallel connected cells,

(i) said anode being connected in series with said relay coil,

(j) said grid being connected to the other side of said parallel connected cells.

6. The invention as defined in claim 5 and including a potentiometer connected in series with said cells connected in parallel.

7. For use in an elevator car, a load determining means comprising:

(a) a light source centrally located at the top of an elevator car,

(12) a cooperating load determining circuit responsive to the light emanating from said light source,

(0) said circuit including a relay for energizing a bypass circuit to prohibit the elevator car from stopping at succeeding pickup stops when loaded to a predetermined capacity,

(d) and means for automatically controlling the operation of said relay coil when the elevator car has been filled with a predetermined number of passengers,

(e) said latter means including several photoelectric variable resistor cells which are each connected in parallel with respect to one another to define a block, said cells being rendered highly conductive when they sense light from said light source and are rendered less conductive as the amount of light falling thereon decreases,

(f) a normally open switching means connected in series with relay coil and in parallel with said block of photoelectric cells,

(g) said normally opening switching means being actuated to close the circuit to said relay to actuate the same when said photoelectric cells are rendered non-conductive.

8. The invention as defined in claim 7 wherein said switching means comprises a triode electronic tube.

9. The invention as defined in claim 8 wherein the photoelectric cells are connected in parallel with respect to one another between the leads to the grid and cathode of said tube.

10. The invention as defined in claim 9 including a potentiometer disposed in series with a block of parallel connected photoelectric resistor cells.

References Qiterl in the file of this patent UNITED STATES PATENTS 1,887,209 Lucas Nov. 8, 1932 2,366,152 Lauterback Dec. 26, 1944 2,602,524 Shirley Euly 8, 1952 2,713,645 Lerch July 19, 1955 2,900,521 Eames Aug. 18, 1959 2,968,366 Drexler Jan. 17, 1961 

1. IN COMBINATION WITH AN ELEVATOR CAR, AN OVERLOAD LIMITING MEANS COMPRISING A LIGHT SOURCE LOCATED IN THE ELEVATOR CAR, A SERIES OF LIGHT RESPONSIVE MEANS SPACED ABOUT THE WALLS OF THE CAR, A RELAY ADAPTED TO BE ACTATED TO EFFECT THE BY-PASSING OF A STOP WHEN SAID CAR IS LOADED TO A PREDETERMINED MAXIMUM SAFE CAPACITY, SAID RELAY BEING CONNECTED IN A CIRCUIT WITH SAID LIGHT RESPONSIVE MEANS WHEREBY SAID RELAY IS ACTUATED WHEN A PREDETERMINED AMOUNT OF LIGHT BEAMING FROM SAID LIGHT SOURCE ON SAID LIGHT RESPONSIVE MEANS IS INTERRUPTED BY THE LOAD CARRIED IN THE ELEVATOR. 